Nursing home patients suffer from chronic diseases which place them at great risk from dysmobility yet few receive rehabilitation services. This study will examine the effects of a theoretically derived exercise program on frail nursing home residents. The impact of the intervention on axial mobility and how this relates to various levels of physical and psychosocial function will be explored. The exercise program focuses on basic motor patterns, (Snow's Intermediate Functional Tasks--SIFT) which comprise more complex activities of daily living. The study will consist of two phases. The first phase will be a cross-sectional study of 140 nursing home residents to examine the test properties of the SIFT assessment instrument, and to examine its relationship with other measures of physical and functional performance. This phase of the study will also include feasibility testing of a group exercise program which is based on the SIFT, and prescribed through the use of an algorithm. After refinement in phase I of the exercise protocol, a limited intervention trial utilizing a placebo controlled cross-over design will be conducted. 96 nursing home patients will be recruited for phase II. Subjects will be randomized to participate in a three times a week exercise group or a social-activities group. The intervention (placebo or exercise) will last four months prior to cross-over. Outcomes to be analyzed will address disability, functional limitation, impairment, and cost-effectiveness. The primary outcome measures for phase II are the Functional Independence Measure (FIM), and the Multidimensional Observational Measure of Elderly Subjects (MOSES). All measures will be repeated at monthly intervals throughout the intervention.